Corynebacterium Species Causing Urinary Tract Infections

Aims: To determine the prevalence and to assess the antimicrobial susceptibility of individual Corynebacterium species isolated from patients with urinary tract infections.

Place and Duration of Study: Department of Medical Microbiology, Infant Jesus Teaching Hospital, Warsaw, Poland from January 2010 to December 2016.

Methodology: This retrospective analysis included Corynebacterium strains derived from 211 urine samples. Microbial identification had been performed with the use of biochemical panels and matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOF MS). Antibiotic susceptibility tests were conducted according to the Polish Reference Center for Antimicrobial Susceptibility and the European Committee on Antimicrobial Susceptibility Testing guidelines.

Results: The predominant Corynebacterium species isolated from female urine were C. coyleae, C. aurimucosum, and C. amycolatum. The following species: Arcanobacterium haemolyticum, C. freneyi, C.group G1, C. muciefacines, C. propinquum, C. pseudodiphtheriticum, and C. renale were identified only in urine cultures from female patients. Antimicrobial susceptibility rates were 41.9% for penicillin, 53.4% for ciprofloxacin, 83.3% for gentamycin, and 77.8% for tetracycline with all the evaluated strains susceptible to vancomycin.

The number of the Corynebacteria species isolated from urine samples consecutively raised from 4 in 2010 up to 87 in the last analysed year.

Conclusion: The observed increase in the number of Corynebacterium species isolated from urine samples over the years indicates the important role of these bacteria in the urinary tract infection epidemiology, especially in women. Therefore, novel diagnostic procedures should be developed for the specimens from patients with urinary tract infections, especially in the case of transplant recipients.